Q3 - Statistics reveal that more collisions

[samuelfbaron]

I really got stuck between (B) and (E).

I understand the flaw here, but why is (E) exactly wrong?

[sumukh09]

Let's break down E so we understand exactly what it's saying. You know what the flaw here is, so E should parallel that.

E says "it takes statistical evidence that fails to support a conclusion concerning the safety of bicyclists" ---- What conclusion concerning the safety of bicyclists are they talking about? And then it says "as evidence that proves the opposite conclusion" ------- the opposite conclusion being "adding lanes is unlikely to enhance the safety of bicyclists"

"proves" is too strong - nothing is being proved here.

And it's unclear what conclusion the statistical evidence is failing to support.

[aznriceboi17]

I had a similar question about E. Because it is worded so vaguely, it seems to me that you could read it as saying:

The argument takes statistical evidence (more collisions between bikes and MVs on roads with bicyle lanes) that fails to support a conclusion (the evidence certainly does not by itself support the conclusion that bike lanes enhance safety of cyclists) as evidence that proves the opposite conclusion (bike lanes are unlikely to enhance safety for cyclists).

The very fact that the argument is described in such general terms seems to make it easy to fit a wide variety of arguments into its description.

I guess the 'proves' language is a bit strong, but could someone point out any other difficulties with the matching I described above? One thing that made me hesitate is that 'statistical evidence that fails to support a conclusion' on the LSAT usually refers to evidence that was gathered explicitly in an attempt to prove a particular hypothesis. Ie, in the LSAT stimuli it usually comes in the form of an experiment designed to prove a hypothesis which only resulted in inconclusive evidence.

The statistics cited here don't seem to fit that mold since there's no clear indication that it was gathered to support the conclusion that adding bicycle lanes enhances safety for cyclists.

[magic.imango]

I'm completely lost with this question. I don't understand how (B) is the flaw in the argument. Can someone please help me through this core?

Core:
Statistics reveal more collisions on roads with lanes than w/o ---> having lanes not likely to make lanes safer

What does there being more bikers riding in the bike lanes have to do with the bike lanes not being any safer???

[rinagoldfield]

This is a flaw question. The process for this question type is to find the argument core, evaluate the reasoning error, eliminate wrong answer choices, and confirm the right answer.

The argument core is:

There are more bike accidents on roads with bike lanes
-->
Adding bike lanes to existing roads won’t help bicyclists

This argument makes a classic causation/ correlation error. Accident rates and bike lanes are correlated; the author assumes that the lanes cause the accidents. He or she overlooks other possible interpretations of this correlation. For example, perhaps the streets with bike lanes are extremely dangerous, even more dangerous than the streets without bike lanes. In this case, the bike lanes might prevent many accidents even as those streets continue to be dangerous.

Now to the answer choices:

(A) Is irrelevant. It doesn’t address our given premise, which concerns the rate but not the severity of the accidents.
(B) Seems promising… it offers another reason as to why the accident rate might be high on streets with bike lanes. Hold onto this one for now.
(C) Is extreme. It talks about ANY road alteration. It is also out of scope, discussing the safety of motorists rather than the safety of bicyclists.
(D) Seems relevant… but wait! The premise it describes (“only some roads that currently have such lanes are safe”) is NOT the premise offered by the author (“There are more bike accidents on roads with bike lanes”). Eliminate this answer choice.
(E) Huh? The author does not interpret the data in this way. This is one of those answer choices that is tempting because it is confusing. Don't be so tempted!

(B) is correct. It offers a third cause of the accidents that the author overlooked.

Hope this helps.
Best,
Rina

[can_I_ever_reach_a_170?]

I somehow had difficulty seeing B as a correct answer choice.
I was looking for an answer choice that says something like adding such lanes is actually going to be safer to bicyclists. (Something about the safety of biclyclists the author has overlooked)
And B just seemed like explaining the current situation of many bicyclists on roads having specific biclycle lanes.
Or is B saying that there are many bicyclists on such roads (that adding such lanes would be safer to bicyclists?)
I don’t like B because it doesn’t directly support the idea or say that adding such lanes would make the roads safer to bicyclists.

Is there something wrong with how I read and understand?

[ohthatpatrick]

Yeah, I think the problem with your thinking is that you’re too narrowly thinking about what it means to weaken/criticize an argument.

You’re thinking of it as, “I need to advance evidence that goes AGAINST THE CONCLUSION”. That’s one way!
But “undermining the value/relevance of the EVIDENCE” is another way.

Say you’re the lawyer who’s defending Eddie against charges that he robbed a bank.

Both of these moves would help your case and hurt the prosecutor’s case:
1. Eddie is extremely wealthy from owning a successful business and he has a documented fear of confrontations. HE certainly doesn’t sound like a bank robber. (COUNTEREVIDENCE AGAINST THE CONCLUSION)

2. The bank teller who claims to have seen Eddie rob the bank wasn’t wearing her strong prescription glasses at the time the bank was robbed. (UNDERMINING THE VALUE/RELEVANCE OF THE EVIDENCE)

When you’re doing Flaw / Weaken / Strengthen / Evaluate, it’s helpful to play the role of Opposing Counsel. That role is to represent the Anti-Conclusion, as your “client”.

If the author is concluding “Eddie robbed the bank”, then Opposing Counsel is representing the position of “Eddie didn’t rob the bank”. You can think about ways to respond to the prosecutor’s evidence, or you can advance your own evidence.

Here, the author is concluding “Bike safety lanes don’t increase safety”. We need to think we’re the lawyer representing the position of “Bike lanes DO increase safety” (as you were).

We can either respond to the author’s evidence or we can advance some counter-evidence of our own.
1. responding to the author’s evidence: “Yes, MORE bike accidents occur on lanes with bike roads, but those are major roads, so of course the raw number is higher. There are more accidents because there are way more bikers. But there would be EVEN MORE bike accidents on those major roads if we didn’t have the bike lanes there.”

2. introducing your own counterevidence: “Statistics also show that fewer INJURIES occur on lanes with bike roads since the collisions that occur on roads with bike lanes are at much lower speeds and cause much less danger to the bike riders.”